The present invention relates to a torque transmission device.
Vehicles comprising a front engine and a rear or all-wheel drive have a drive shaft that leads from the transmission output to the input of the rear axle gear. At present, drive shafts of this type normally consist of steel. They have a correspondingly high weight and contribute considerably to the overall-mass moment of inertia of the vehicle.
It is an object of the invention to provide a torque transmission device, particularly a drive shaft, for a drive train of a vehicle, which has a lower weight than conventional drive shaft arrangements.
This and other objects are achieved by a torque transmission device having a shaft, particularly a “drive shaft” for a drive train of a vehicle, and at least one coupling or flange element that is connected with an end of the shaft. The coupling or flange element is provided for coupling the shaft with another component, such as an output flange of a vehicle transmission or a drive flange of an axle gear. The term “shaft” therefore particularly comprises shafts generating positive vehicle drive. The shaft, as well as the at least one coupling element, consists at least partly, but preferably completely, of a fiber-reinforced plastic material. The plastic material may particularly be a carbon-fiber-reinforced and/or a fiber-glass-reinforced plastic material. The shaft and the coupling element do not necessarily have to consist of one and the same plastic material but may be made of different materials.
According to a further development of the invention, the at least one flange element has several arm-type elements which are uniformly spaced from one another in a circumferential direction of the flange element. The flange element may, for example, have a star-type or triangular shape with three “connection points” mutually spaced by 120 degrees respectively in the circumferential direction. A hole may be provided at each of the “connection points”. The holes are preferably situated on a common hole circle. Naturally, more than three connection points, for example, four, five or six connection points can also be provided.
According to a further development of the invention, the at least one flange element has a ring-type section which is pushed onto the shaft or onto the shaft end. Arm-type elements project radially outward from the ring-type section.
According to a further development of the invention, two groups of arm-type elements are provided which, in a front view of the shaft, are each situated in pairs in a row and are spaced with respect to one another in the axial direction of the shaft. The two groups of arm-type elements can be an integral component of one and the same flange element; i.e. they may be connected with one and the same ring-type section. As an alternative, two separate flange elements with one group of arm-type elements respectively may also be provided. In a front view of the shaft, the two flange elements are aligned such that the arm-type elements are each situated in pairs in a row.
According to a further development of the invention, the ring-type section of the flange element or the ring-type sections of the flange elements forms or form a press fit with the shaft. At their ring-type sections, the flange element or elements can additionally be glued to the shaft or be form-lockingly connected with it in the circumferential direction, so that also high torques can be transmitted from the flange element or flange elements to the shaft and vice-versa.
For illustrating a particularly tight press fit, a “circumferential bandage” can additionally be provided which is wound onto the outer circumference of the ring-type section of the flange element or the ring-type sections of the flange elements. The circumferential bandage may also be made of a fiber-reinforced plastic material. As an alternative, the circumferential bandage may also be made of a different material. It is generally used for pressing the ring-type section or ring-type sections to the shaft, which permits the transmission of high torques.
According to a further development of the invention, a respective nth arm of the first flange element is connected by way of a rod-type or pin-type tension element of a first group of tension elements with an assigned nth arm of the second flange element. The rod-type or pin-type tension elements are therefore arranged parallel to the longitudinal direction of the shaft.
According to a further development of the invention, a second group of tension elements is provided, which can also be constructed in a pin-type, rod-type or roller-type fashion. Like the first group of tension elements, the second group of tension elements is mutually spaced in a uniform manner in a circumferential direction of the flange element or of the flange elements, in which case, viewed in the circumferential direction of the at least one flange element, a first tension element is in each case followed by a second tension element, and vice-versa.
According to a further development of the invention, coupling elements are provided, each of the first tension elements being coupled by way of at least one coupling element with the second tension element that is next in one circumferential direction, and being coupled by way of at least one coupling element with the second tension element that is next in the opposite circumferential direction.
This type of arrangement is known from the assignee's earlier, not pre-published German patent application DE 10 2008 034 214.9, the content of which is expressly incorporated by reference herein, and a portion of which is added herein with respect to the description of FIGS. 1-6.
Thus, it can be provided that each of the coupling elements mutually couples a first tension element and a second tension element adjacent to the first coupling element in the circumferential direction. The coupling elements can be tensioned by use of assigned tension elements. The coupling elements can wrap around the tension elements at least over a partial circumference of the tension elements. More than two coupling elements, particularly a plurality of coupling elements, can be mounted on each of the tension elements.
Analogous to the arrangement described in German patent document DE 10 2008 034 214.9, the first group of tension elements can be coupled with the second group of tension elements also exclusively by way of the coupling elements in the rotating direction.
The individual coupling elements may also be foamed or cast into an elastic coupling element connecting the individual coupling elements.
Furthermore, the rod-type, pin-type or roller-type tension elements may each be equipped at their ends with a step, a disk or the like, which prevents or prevent a slipping-down of the coupling elements off the concerned tension element.
The coupling elements may completely or partially consist of a fiber glass material. In particular, the coupling elements may consist of a plastic material that is reinforced by fibers, particularly glass fibers. The coupling elements may have the shape of oval rings or slings. Finally, the tension elements may have a roller-type, bolt-type or bush-type shape.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.